An array camera includes an array of individual cameras, and is alternatively referred to as a multiple camera imaging system. An example of such an imaging system is a dual camera system that is becoming a popular product feature in mobile phones. Typically, the individual cameras cooperate to provide imaging functionality that cannot be achieved by using only one camera by itself. For example, in stereo imaging, two individual cameras each takes an image of the same scene from two slightly different vantage points, thereby producing a depth perception functionality that is not achievable with a single camera alone. As another example, in dynamic zooming, the dual camera system includes a telephoto lens camera with a narrower but more focused field of view (FOV), and a wide FOV camera with a wider but less focused field of view. These two cameras are directed to each take an image of essentially the same scene, with the telephoto lens camera providing a more zoomed-in view of the scene. The pair of images captured by these two cameras may be processed and then combined to provide a range of zoom levels, thereby producing a dynamic zooming functionality. With only a single camera, such functionality would require a complex, active-type mechanical adjustment of a variable imaging objective.
The abovementioned dual camera operations rely on proper combination or superposition of two images captured by two different cameras that are placed at slightly different positions, thus having slightly different perspective views of the same scene. Prior to image combination or superposition, geometrical corrections are applied to the captured images to rectify each image and to align them with each other. Conventionally, the requisite alignment process is based on comparing pixel values between individual images to find corresponding pixels. Imperfections in this image combination approach result in image objects that may appear misplaced. Moreover, the alignment process is applied to two-dimensional images, and incurs a great deal of computational cost in terms of hardware complexity and lengthy image processing time.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.